Serial hemodynamic studies and simultaneous radionuclide angiography were performed in patients with septic shock. Survivors most commonly developed a profound but reversible depression of left ventricular ejection fraction with concomitant dilatation of the ventricle. These changes returned to normal about one week after the onset of shock. Non-survivors demonstrated one of two patterns: half developed a reversible depression of ejection fraction, the other half demonstrated no change or a decrease in ejection fraction, which progressed until death. Cardiovascular abnormalities induced by sepsis are the most common cause of death in ICU patients. Understanding the cardiovascular changes should allow better treatment of septic shock patients.